HUB-03X 4 mm Washer and 7 mm Washer vs. Wirtgen W6/20X: Compatibility, Application and Selection Guide

Quick Answer

KOIHO HUB-03X is a 20 mm-shank road milling pick with a regular 4 mm stamping washer, while KOIHO HUB-03XD uses a reinforced 7 mm stamping washer. Both models use a 19 mm flat-bottom carbide tip and are recommended for asphalt milling and stabilizing.

The Wirtgen W6/20X² reference pick shown in the supplied data uses a 20 mm shank, a 7 mm washer, and a cap-shaped carbide tip for asphalt-layer removal.

For an installation that requires a 7 mm washer, the HUB-03XD configuration is the closer dimensional starting point. For a 4 mm washer installation, select HUB-03X. Final compatibility should always be verified against the actual toolholder, drum, original pick dimensions, and machine specification.

Product Comparison

What Does the Washer Do?

The stamping washer is part of the milling-pick assembly. According to the supplied technical material, it is made from high-manganese alloy steel, precision stamped, and heat-treated to support wear resistance and help protect the milling-tool shank.

The washer covers the end face of the toolholder, where compressive loading and wear can be concentrated during operation. The supplied material identifies two options: a regular 4 mm washer and a reinforced 7 mm washer.

Washer thickness should not be treated as a cosmetic variation. It affects how the pick assembly seats against the holder and can influence axial position, clearance, and protection at the holder face.

HUB-03X: 4 mm Washer Configuration

HUB-03X is designed with a 20 mm shank, a 19 mm flat-bottom carbide tip, and a 4 mm washer. It is listed for asphalt milling and stabilizing applications.

The 4 mm washer configuration is appropriate when the original pick-and-holder system requires a thinner washer arrangement. Buyers should compare the original part before ordering, especially when a prior replacement tooth may not match the original equipment specification.

HUB-03XD: 7 mm Reinforced Washer Configuration

HUB-03XD has the same 20 mm shank and 19 mm flat-bottom carbide tip dimensions shown for HUB-03X, but uses a 7 mm washer and has a stated weight of 330 g per pick.

The 7 mm washer is described as reinforced in the supplied washer information. This configuration is relevant when the original pick assembly requires a 7 mm washer or when the purchaser needs the corresponding seating and holder-face coverage arrangement.

Wirtgen W6/20X² Reference Configuration

The Wirtgen W6/20X² drawing identifies a cap-shaped carbide tip for removing asphalt layers, a 20 mm shank for installation in the toolholder bore, and a 7 mm washer.

The W6/20X² designation provides a useful dimensional reference, but a compatible aftermarket selection should be confirmed through actual measurements and machine documentation. Similar shank diameter alone does not establish complete compatibility.

Flat-Bottom vs. Cap-Shaped Carbide Tips

The supplied carbide-tip information separates road milling carbide tips into flat-bottom, cap-shaped, and plug-tip designs.

Flat-bottom carbide tips, such as those shown on HUB-03X and HUB-03XD, are described for milling complex asphalt layers. Their profile is intended to guide aggregate flow and protect the steel body during milling.

Cap-shaped carbide tips, such as the one shown in the Wirtgen W6/20X² reference, are described for asphalt, concrete, stabilizing layers, regeneration, and soil stabilization. The supplied material states that their stronger waist design is intended to accommodate higher milling impact loads and provide additional wear protection for the steel body.

Tip geometry should be selected according to the pavement material, aggregate abrasiveness, cutting depth, milling-machine configuration, and required holder system—not based on model naming alone.

Which KOIHO Model Is Closer to Wirtgen W6/20X²?

Both KOIHO HUB-03X-4mm washer and HUB-03XD-7mm washer are suitable replacements for W6 series road milling teeth, such as W6/20X2 and W6/20A2

Compatibility Checklist

Before ordering a Wirtgen W6 type replacement, confirm these points:

• Shank diameter: Is the holder bore designed for a 20 mm shank?

• Washer thickness: Does the original system use a 4 mm or 7 mm washer?

• Pick length and projection: Does the installed pick maintain the required drum clearance and cutting geometry?

• Holder condition: Is the holder bore worn, enlarged, damaged, or contaminated?

• Original reference: Can you provide the original part number, machine model, holder type, and photos of the removed pick?

Application Guidance

HUB-03X and HUB-03XD are listed for asphalt. They can be considered for road-maintenance projects where the toolholder system and selected carbide-tip configuration match the application.

The Wirtgen W6/20X² reference is identified for asphalt-layer removal. For concrete, highly abrasive aggregate, or deep stabilization work, discuss the tip profile and carbide grade with the supplier before selecting a pick.

Actual service life depends on multiple jobsite factors, including pavement composition, aggregate hardness, milling depth, machine speed, water supply, tooth rotation, operator practice, and the condition of toolholders.

Frequently Asked Questions

Is HUB-03X a direct replacement for Wirtgen W6/20X²?

HUB-03X shares the 20 mm shank size shown in the Wirtgen reference, but it uses a 4 mm washer while the Wirtgen W6/20X² drawing shows a 7 mm washer. But this doesn't affect its use.

Is HUB-03XD closer to Wirtgen W6/20X²?

Yes. HUB-03XD and the Wirtgen W6/20X² reference both use a 20 mm shank and show a 7 mm washer.

Why does washer thickness matter?

The washer protects the holder end face and affects how the pick assembly seats in the holder. A 4 mm or 7 mm washer; it depends on your needs.

What should I send to KOIHO for model confirmation?

Send the original part number, machine model, holder model, photos of the used pick and toolholder, plus measurements of shank diameter, washer thickness, washer diameter, and overall pick length.

Request a Compatibility Check

KOIHO Better Carbide supplies road milling teeth, carbide tips, washers, and related wear parts for asphalt milling and stabilizing applications. For a more accurate Wirtgen-type replacement recommendation, provide your original pick information and holder details before ordering.

Need help choosing between HUB-03X and HUB-03XD? Contact KOIHO Better Carbide for drawings, samples, and application-based selection support.